If you are on Windows 10 or 7 you have to rotate the picture and save it.

Windows 10 is the one in black, if you double click an image in windows 10 this should pop up unless you changed your default program. You can also get the one in white which is windows 7ish by right clicking on the image and choosing to open it with the Windows Photo Viewer.

If you are on Windows 7 then the default should be the white one which is Windows Photo Viewer, again unless you have changed your default program.

I only have the problem when posting from my iPad or iPhone. Photo orientation all looks normal until I hit post. Then it's a crap shoot of how it displays. All the pics I have posted were taken with the same camera orientation...mostly from my iPhone... so I have no idea what's happening.